Where St. Patrick stands today, farmland and groves stood in the 1880’s. New catholic churches began springing up in neighboring counties. Largo had not grown as rapidly as much of the rest of Pinellas County, but by the mid 1950’s things began to change with industrial plans moving into the area. In 1957 Archbishop Hurley of the diocese of St Augustine was informed that catholic growth was taking place in Largo. Unfortunately, they were being forced to attend Mass in Clearwater and Indians Rocks beach as those were the nearest churches. As a result, Fr Scully, Administrator of Sacred Heart Church in Pinellas Park, was given the task of opening an outpost mission in Largo.
The first Mass was celebrated on January 9, 1958 at the old Large Theater, owned by a local Catholic business owner. Within a few weeks, new arrangements needed to be made as the Theater was unable to hold the number of people attending Mass. In 1958, large tracts of land that once held orange groves became available for purchase. A section of this property was sold to the Diocese in 1958. On June 7, 1958, a Decree of Erection was signed. Fr. Scully was named Administrator and Fr. John McCall was named assistant. On March 12, 1960, Fr. John McNulty celebrated Sunday Mass in what is now St. Patrick Catholic Church.